MOSCOW – World War II may be slipping into distant memory for most Americans and western Europeans, in part because they have all long since agreed on the conflict's basic narrative.

But Russians and many eastern Europeans continue to furiously dispute the war's causes and results, almost as if it were still going on. That acrimony is likely to be on full display when Russian Prime Minister Vladimir Putin meets other European leaders in Gdansk, Poland, on Tuesday to mark the 70th anniversary of the Nazi invasion of Poland, which triggered a six-year war that claimed more than 50 million lives.

Many Poles, joined by leaders from Estonia, Latvia, and other post-Soviet states, are demanding that Moscow use the occasion to make a clean break with its Soviet past by apologizing for the August 1939 Molotov-Ribbentrop pact, and its secret provisions under which Germany and the USSR colluded to divide eastern Europe between themselves.

A weekend survey conducted by the Warsaw newspaper Rzeczpospolita found that 76 percent of Poles want Mr. Putin to say he's sorry for the bargain between Adolf Hitler and Soviet leader Joseph Stalin, under which Poland was ripped apart and shared between the two dictatorships. Thousands of Polish military officers were subsequently murdered by the Soviet secret police and buried in the Katyn forest, in western Russia, and as many as half a million Poles were exiled to Siberia.

"Apologize for attacking Poland, for the Katyn genocide, for murdering our heroes, for sending Poles to Siberia," a Monday editorial in another Warsaw paper, Super Express, urged Putin.

"You cannot deny these crimes," it said.

Following the war, the Soviet Union was permitted to keep the territories it had gained under its deal with the Nazis, including eastern Poland, the Baltic states of Lithuania, Latvia, and Estonia, as well as Moldova, and even part of Germany.

Many of those countries, liberated after the Soviet collapse, have joined NATO and the European Union in recent years, but their anger about the long winter under communist rule has yet to subside.

"Everyone is struggling to build a new identity for themselves, but as soon as we touch upon any key foreign policy issue all of the unresolved feelings from the war come rushing back," says Dmitri Suslov, an expert with the independent Council on Foreign and Defense Policies in Moscow. "They still blame Russia for the long occupation of their countries," he says.

But in Russia, where the very existence of the secret Soviet-Nazi deal was officially denied until 1991, a poll conducted last week by the independent Public Opinion Research Center in Moscow found that 63 percent regard the Molotov-Ribbentrop pact as a necessary decision by Mr. Stalin aimed at preventing war.

The Russian narrative views the Soviet-Nazi pact as a defensive step taken in the wake of the Western allies' 1938 bargain with Hitler at Munich, where Czechoslovakia was handed over to Germany in exchange for a brief illusion of peace.

In an open letter to the Polish newspaper Gazeta Wyborcza on Monday, Putin admitted that the deal with Hitler was a "crime" but denied that it was a major cause of WWII. Instead of an apology, he called for "forgiveness."

"Our duty is to do everything to relieve Russian-Polish relations of the burden of mistrust and prejudice, to start a new chapter in relations," Putin wrote.

Experts say Russia's inability to simply renounce Soviet crimes and turn a fresh page is bound up with its self-image as a superpower, which was a key outcome of the Soviet victory over Nazi Germany.

"When Moscow fights against 'revisionism' in the interpretation of WWII, it is really trying to combat the degradation of Russia's international status following the collapse of the USSR, and to insist that Russia is still a major player," says Mr. Suslov.

Eastern Europeans are still railing against Moscow, almost two decades after the Soviet Union's demise, in part because they are not yet fully in tune with their new identities as Western states, some experts suggest.

"In western Europe they set aside their historic enmities and traumas in the interests of integrating into a united Europe and, while they have not forgotten history, they've placed it outside politics," says Fyodor Lukyanov, editor of Russia in Global Affairs, a leading Moscow foreign policy journal.

"In eastern Europe it's the opposite. History remains politicized, and everyone is trying to build their national identity through historical dispute. That's why, in this part of the world, we're still arguing over who started World War II."